> ## Documentation Index
> Fetch the complete documentation index at: https://docs.summand.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Data sources overview

> Every source Summand supports, what it's good for, and which tier it requires.

Summand has five built-in connectors plus a universal **Fivetran** path that handles everything else. Pick the one that matches how the data lives today; you can mix and match across one account.

| Source                                                                | Best for                                                                                          | Tier required |
| --------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- | ------------- |
| [CSV upload](/data-sources/csv-upload)                                | One-off analyses, files up to 4 GB                                                                | Free +        |
| [PostgreSQL / MySQL / Snowflake / Azure SQL](/data-sources/databases) | Live data in your warehouse                                                                       | Enterprise    |
| [Delta Sharing](/data-sources/delta-sharing)                          | Databricks UniForm shares with Iceberg metadata                                                   | Enterprise    |
| [Fivetran](/data-sources/fivetran)                                    | Anything Fivetran supports — Databricks (non-UniForm), Redshift, Oracle, BigQuery, 300+ SaaS APIs | Enterprise    |

## How to choose

<CardGroup cols={2}>
  <Card title="One-time analysis on a file you already have" icon="file-csv" href="/data-sources/csv-upload">
    Use **CSV upload**. No setup, no credentials.
  </Card>

  <Card title="Live data from a SQL warehouse" icon="database" href="/data-sources/databases">
    Use the **database connector** for Postgres, MySQL, Snowflake, or Azure SQL — direct connection, lowest latency.
  </Card>

  <Card title="Databricks with UniForm enabled" icon="diamond" href="/data-sources/delta-sharing">
    Use **Delta Sharing** — Iceberg-backed, type-faithful, incremental refresh.
  </Card>

  <Card title="A source not natively supported" icon="bolt" href="/data-sources/fivetran">
    Use **Fivetran** — anything Fivetran can sync, Summand can analyze.
  </Card>
</CardGroup>

## What every source has in common

No matter the source, Summand:

* **Curates a Parquet copy** of your data on first analysis. The source isn't queried again until refresh.
* **Generates a semantic-layer version** with the same artifacts (column stats, EBM, surprises, UMAP).
* **Enforces the same authorization** (grants + visibility) regardless of source.
* **Charges the same** for analysis — pricing is per-account, not per-source.

The differences between sources are in **setup**, **credential handling**, and **refresh model**, not in what you can do once a dataset exists.

## Refresh model by source

| Source                                              | Refresh trigger         | Notes                                                                             |
| --------------------------------------------------- | ----------------------- | --------------------------------------------------------------------------------- |
| CSV                                                 | Re-upload               | Immediate. Replaces the file in place.                                            |
| Database (Postgres / MySQL / Snowflake / Azure SQL) | Manual *Refresh* button | Full table re-read each time.                                                     |
| Delta Sharing                                       | Manual *Refresh* button | **Incremental** — only changed partitions are re-read.                            |
| Fivetran                                            | Manual *Refresh* button | Re-reads Fivetran's most recent sync output; doesn't trigger a new Fivetran sync. |

## Privacy and credentials

* **CSV** uploads stream directly to Summand's encrypted S3 bucket via presigned URLs. The file never passes through any application server.
* **Database** credentials are encrypted at rest in AWS Secrets Manager. Plaintext is never logged.
* **Delta Sharing** bearer tokens are stored encrypted in Secrets Manager; rotation is supported from the connector edit page.
* **Fivetran** holds your source credentials — Summand only sees the Parquet output. Your warehouse password never touches Summand servers.